The hot gas generator of the above-noted type according to the prior art comprises an oil pump for lubricating a bearing portion supporting a common rotary shaft extending between the compressor and the turbine, and starter means such as a motor, blower or the like for starting the compressor. At a starting time, the oil pump is first actuated to lubricate the bearing portion and then the starter means is actuated to supply air and fuel gas to the combustion chamber where a mixture of the air and fuel gas is ignited. At a stopping time, the fuel gas supply is discontinued and an oil cooler for preventing fusing of the bearing portion is stopped after a certain time lapse.
However, the above series of operational steps are taken manually, and it is therefore necessary for the operator to ensure each of the steps including supplying of lubricating oil, ignition, and self-sustaining operation of the generator by reading varied meters and the like. Misoperations by the operator could lead to serious consequences. For example, the bearing portion will be damaged when the generator is started with insufficient lubricating oil supply. In particular, a mistiming of the supply of fuel gas and air and the ignition may result in generation of incomplete combustion gases or even a danger of explosion.